Interest-computer.



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G. C. WILD.

INTEREST COMPUTER.

APPLICATION FILED JAN.26,1914.

L MW pm See Above SeeBelow CHARLES C. WILD. OF DUBUQUE, IOWA.

INTEREST-COMPUTER.

Specification of Letters Patent. Application filed January 20, 1914. Serial no.

' Patented Oct. 20, 1914. 814,490.

To (17lu lz 0m it may concern:

Be it known that I, CHARLES C. WILD, a citizen of the United States, residing at Dubuque, in the county of Dubuque and State of Iowa, have invented certain new and useful Improvements in Interest-Computers; and Ido hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in devices for computing interest and comprises a simple and efiicient device of this nature having various details of construction and combinations and arrangements of parts which will be hereinafter fully described, shown in the accompanying drawings and then specifically defined in the appended claims.

I illustrate my invention in the accompanying drawings, in which igure 1 is a plan view of the device. Fig. 2 is a view, parts being cut away to better illustrate features of the invention. Fig. 3 is a cross sectional view on line 33 of Fig. 1, and Fig. 4 is a detail view of one of the slides removed from the jacket or casing.

Reference now being had to the details of the drawings by letter, A designates a casing which is made of paper or other suitable material and is open at its end and scalloped away as at B for convenience of the operator in taking hold of the sliding strips which will be hereinafter described. The front of said casing or jacket is provided with series of apertures C, D and E near each end, the aperture at the extreme left being adapted to designate hundreds, the central apertures tens and the extreme right aperture E units, to designate the principal upon which it is desired to compute the interest. Said jacket or casing, it will be noted, is provided with two central longitudinal partitions, designated respectively by letters F and G, and the front wall of the jacket has a transverse slot H formed therein through which may be seen the interest upon the principal which will have been automatically displayed by the manipulation of the slides upon which the figuring is printed.

Openings, designated by letters are formed in the front wall of and through which the per cent. of interest to be computed may be seen. A second transverse slot is designated by letter O and at which the interest may be rated at a certain per cent. upon the principal disclosed at the apertures upon the lower end of the jacket.

Upon reference to Fig. 3 of the drawings will be seen a card I, having two rows of series of diagonally disposed slots arranged in step relation one with another, the upper series being designated by letter I and the lower series by P. Said card is adapted to have a longitudinal movement intermediate the partition F and the front wall of K and L, the jacket the acket, one end thereof projecting above:

the upper end of the jacket and serves as a means whereby the operator may grip the card to move the same back and forth. Said partition F is provided with transverse slots F and F which are in registration with the slots H and 0 respectively and intermediate'the two partitions F and G are pockets to hold and grip the longitudinal strips R, R and R which have printed thereon a series, designated by letter R from 1 to 9 and which are adapted to be disclosed at one or another of the apertures C, D or E, the series of numerals on the strip R adapted to disclose hundreds, those upon the strip R tens and those upon the strip R units at the apertures to designate the principal upon which it is desired to compute interest at a certain per cent. The strip R has printed thereon in series the interest at difi'erent rates upon the amount disclosed at the opening R has the computed interest at certain rates of interest upon the various amounts disclosed at the aperture D, while the card or strip R has the computed interest upon the amount of units disclosed at the aperture E.

The operation of the invention is as follows: Suppose it is desired to compute the interest upon $351.00 at 3%. The three cards R, R and R are moved to disclose the numerals 351 at the sight apertures G, D and E, and-the'card I is moved in order to disclose the 3% amount of interest to be computed at the aperture K. This movement of the card will also bring the numeral 3% opposite the aperture L, representing the amount of interest upon the same principal which may be computed at C, while the strip 3%%. The eards'being adjusted as shown, the amount of interest on $300 at 3% would be disclosed at the extreme end of the slot 0 and would be $9.00, while the same rate of interest upon $50.00 disclosed at the aperture D would be $1.50, while 3% upon the unit $1.00 would be .03 and which added together would make. $10.53, whereas the interest upon the same principal at 31}% would be disclosed at the three sets of figures disclosed through the slots H. By the arrangement of the figures upon the various cards, it will be noted that all that is necessary is to designate ,first the amount of the principal through the sight apertures at the lower end of the jacket, after which the rate of interest is disclosed at either one of the sight apertures K or L and the correct amounts upon each will be designated and which may be readily added up.

What I claim to be new is 1. A device for computing interest com prising a jacket having series of sight apertures near one end through which the amount of principal may be disclosed and other slots for the disclosure of the rates of interest in the face of the jacket, a card having diagonally disposed series of slots therein and bearing upon its face different rates of interest to be disclosed at sight apertures in said jacket, a series of cards movable within the jacket and bearing numerals designating the interest. at different per cent. and adapted to be disclosed through the diagonally disposed series of said slots, as set forth.

2. A device for computing interest comprising a jacket having series of sight apertures near one end through which the amount of rincipal may be disclosed and other slots or the disclosure of the rates of interest in the face of the jacket, a card having diagonally disposed series of slots therein and bearingupon its face difierent rates of interest to be disclosed at sight apertures in said jacket, a portion of the jacket being folded upon itself and provided with transverse sight apertures, a series of cards bearing numerals designating the interest at different per cents. and which are adapted to be disclosed through said transverse slots, diagonally disposed slots and the slots in the jacket.

3. A device for computing interest comprising a jacket having series of sight apertures near one end through which the amount of principal may be disclosed and other slots for the disclosure of the rates of interest in the face of the jacket, a card having diagonally disposed series of slots therein and bearing upon its face dillerent rates of interest to be disclosed at sight apertures in said jacket, pockets formed within the jacket, cards, having printed thereon numerals designating interest at different per cents, and movable within said pockets and designed to disclose numerals through said diagonally disposed slots and slots in the jacket.

In testimony whereof I hereunto afiix my signature in presence of two witnesses.

CHARLES C. WILD.

Witnesses HENRY HoL'rz, JOHN T. DEMPsEY. 

